Originally a supplicatory prayer, especially when liturgical or ceremonial; later, a liturgical prayer in which the clergy lead and the laity respond, the same form of response being repeated in a number of succeeding clauses, and usually being of a penitential character. A litany is a separate service in itself and as such is often said in processions. It is also used as a portion of the services on certain days. Litanies are to be used for public devotions and at public services only when approved by the pontiff for this purpose. Those not so approved may be used for private devotions only. Only five litanies are approved for public devotions